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There was a lot of hype a couple years ago on how the dimples really help with flight trajectory and wind resistance. Companies were coming up with baseballs, footballs, etc, even bats that had dimples in them. They said it was going to revolutionize sports. Well guess what, you don't see em at all today do ya, except on golf balls.

not sure what it would do for paintball and it's flight in the air or anything. but the dimples actually do have advantages in golf and skiing(yes skiing). Not sure what they do in golf since i ahven't ever played and never pay attention to it. but skiing thats another thing. the ski's I have are dimpled like the surface of a golf ball to lower the friction and turbulance the ski aquired as it goes across the snow

actually, they ARE in proportion to golf balls, sorta. and thats the problem.

the problem is, on something this small, tiny impurities in the surface can do the same thing as dimples. in a fluid dynamics book a read, a 3 inch rough sphere had 5 times less drag at 125 mph winds than a smooth one. and the roughness was in the form of scores only .003" deep.

we want a lot of turbulance in the boundary layer on paintballs, and i think at this size and speed, dimples arent the way to get it. a rough surface woulde be better.

AGD, have you tried smooth against one roughened with, say, 100 grit sandpaper?

I thought dimples on golf balls were beneficial because of spin. I don't think paintballs spin so fast that dimples would make any difference whatsoever (as shown in the data thread). Wouldn't this be the same reason you don't see dimpled baseballs, footballs, etc.? It's not like I want my paintballs to land 10 ft. past my target and roll backwards to it.

nope, the point of dimples is to cause a turbulant boundary layer, thereby decreasing drag (funny, huh, decreasing drag by making it turbulent). this moves the point of seperation (of the boundary layer and ball) backwards, so the "wake" of the object is smaller. because its the wake that causes drag. this works at high reynolds numbers (moving fast or with a really thin fluid).

with golf balls, the dimples are the perfect solution, because they can do that without creating wierd flight patterns (like taking your drive to the back of the head...) when there is a bit of spin. this wouldnt really be important in paintball because they dont spin very fast, especially when compared with a golf ball. most of the time you can see the spin while watching a paintball (with two-tone shells).

Forgive my overall lack of fluid dynamics knowledge, but the wake vortices cause a lot of the drag when an object moved through a fluid. Submarine technology for example tries to focus on moving those away from the sub, which decreased drag. Or in an airplane, you have probably heard of wingtip vortices. When those are disrupted by ground effect or winglets, there is a significant increase in performance.

kinda, golf ball dimples are there because of spin, specifically to reduce drag without worrying about spin too much.

its all about the turbulence (vortices, actually little low pressure zones, "sucking" on the ball, as it were) in the wake. the smaller the wake, the less drag, meaning the ball will decelerate slower and go farther.

this is why airplane wings have the blunt end in the front, as it has little to do with drag. the thin, tapered tail allows the wake to be extremely thin.

The first one is the air flow over a smooth ball. The second one is air flow over a dimpled ball. The smooth ball has a larger area where the air seperates from the flow around the ball and it creates more drag. The more turbulent flow around the second ball has more air flow around the ball and less area where the air seperates from the air flow and starts swirling around and stuff like that, so less drag.

Originally posted by sniper1rfa this is why airplane wings have the blunt end in the front, as it has little to do with drag. the thin, tapered tail allows the wake to be extremely thin.

I was reading about putting things in orbit with railguns. They were talking about how at hyper-sonic speeds you do see a significant decrease in drag with a pointed nose vs. a rounded nose. The problem was that the pointed nose wasn't able to disapate the heat as well as the rounded nose. The conclution they came to was that it would actually be pretty easy to get cargo into orbit with a railgun once we developed material that could withstand the heat a reshaped launch vehicle would be subjected to.

Now keep in mind that this was talking about mach 7+ and isn't really relevent to paintball. I just thought you'd find it interesting. I wish I could that paper now, It was an interesting read.

i dont think they would work cuz it would make the balls curve dramatically. Its in a popular sicece. I has a buch of stuff in golf and like a shallow dimpled ball would travel farther and with less spin so it would go straighter.

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"the problem is, on something this small, tiny impurities in the surface can do the same thing as dimples. in a fluid dynamics book a read, a 3 inch rough sphere had 5 times less drag at 125 mph winds than a smooth one. and the roughness was in the form of scores only .003" deep. "

So would this mean that the mild roughness of the RPS advantage paints might actually have some value?